ABSTRACT
An increasing obese population in the United States focuses attention on the effect
of obesity on surgical outcomes. Our objective was to see if obesity, determined by
body mass index (BMI), contributed to bleeding in coronary artery bypass graft (CABG)
surgery as measured by intraoperative and postoperative packed red blood cell transfusion
frequency and amount and 24-hour chest-tube output. A retrospective chart review examined
150 subjects undergoing single-surgeon off-pump or on-pump CABG surgery between September
2006 and April 2009. BMI groups included normal-weight (BMI <25), overweight (BMI
25 to 29), and obese (BMI ≥30). Analyses used a chi-square test to determine variances
in number of transfusions, and ANOVA for transfusion amount and 24-hour chest-tube
amount. The percentage of subjects receiving intraoperative transfusions varied significantly
by BMI group (p = 0.022). The percentage of subjects receiving transfusions in the 72-hour postoperative
period showed a decreasing linear trend based on BMI group (p = 0.054). The percentage of subjects receiving transfusions in the combined intraoperative
or 72-hour postoperative period showed a decreasing linear trend based on BMI group
(p = 0.054). The transfusion amount during the 72-hour postoperative period varied significantly
between BMI groups (p = 0.021), and the test for a linear decrease across groups was significant (p = 0.020). Twenty-four hour chest-tube output showed variation across all three BMI
categories (p = 0.018) with chest-tube output decreasing with increasing obesity in a linear fashion
(p = 0.006). Transfusion rate and amount indicate total blood loss is decreased in the
obese, and chest-tube output findings give a direct measurable indicator of blood
loss from the surgical site indicating increasing BMI is linearly correlated with
decreasing postoperative bleeding.
KEYWORDS
Obesity - BMI - CABG - postoperative bleeding - chest-tube output
REFERENCES
- 1 World Health Organization. Unhealthy Diets & Physical Inactivity. NMH Fact Sheet.
June 2009. Available at: http://www.who.int/nmh/publications/fact_sheet_diet_en.pdf Accessed May 14, 2011
- 2
Birkmeyer N J, Charlesworth D C, Hernandez F et al..
Northern New England Cardiovascular Disease Study Group. Obesity and risk of adverse
outcomes associated with coronary artery bypass surgery.
Circulation.
1998;
97
1689-1694
- 3
Kuduvalli M, Grayson A D, Oo A Y, Fabri B M, Rashid A.
Risk of morbidity and in-hospital mortality in obese patients undergoing coronary
artery bypass surgery.
Eur J Cardiothorac Surg.
2002;
22
787-793
- 4
Lindhout A H, Wouters C W, Noyez L.
Influence of obesity on in-hospital and early mortality and morbidity after myocardial
revascularization.
Eur J Cardiothorac Surg.
2004;
26
535-541
- 5
Engel A M, McDonough S, Smith J M.
Does an obese body mass index affect hospital outcomes after coronary artery bypass
graft surgery?.
Ann Thorac Surg.
2009;
88
1793-1800
- 6
van Straten A H, Bramer S, Soliman Hamad M A et al..
Effect of body mass index on early and late mortality after coronary artery bypass
grafting.
Ann Thorac Surg.
2010;
89
30-37
- 7
Reeves B C, Ascione R, Chamberlain M H, Angelini G D.
Effect of body mass index on early outcomes in patients undergoing coronary artery
bypass surgery.
J Am Coll Cardiol.
2003;
42
668-676
- 8
Spiess B D.
Cardiac anesthesia risk management. Hemorrhage, coagulation, and transfusion: a risk-benefit
analysis.
J Cardiothorac Vasc Anesth.
1994;
8
(1, Suppl 1)
19-22
- 9
Morton J, Anastassopoulos K P, Patel S T et al..
Frequency and outcomes of blood products transfusion across procedures and clinical
conditions warranting inpatient care: an analysis of the 2004 healthcare cost and
utilization project nationwide inpatient sample database.
Am J Med Qual.
2010;
25
289-296
- 10
Scott B H, Seifert F C, Grimson R.
Blood transfusion is associated with increased resource utilisation, morbidity and
mortality in cardiac surgery.
Ann Card Anaesth.
2008;
11
15-19
- 11
Arora R C, Légaré J F, Buth K J, Sullivan J A, Hirsch G M.
Identifying patients at risk of intraoperative and postoperative transfusion in isolated
CABG: toward selective conservation strategies.
Ann Thorac Surg.
2004;
78
1547-1554
- 12
Elmistekawy E M, Errett L, Fawzy H F.
Predictors of packed red cell transfusion after isolated primary coronary artery bypass
grafting—the experience of a single cardiac center: a prospective observational study.
J Cardiothorac Surg.
2009;
4
20
- 13
Scott B H, Seifert F C, Glass P S, Grimson R.
Blood use in patients undergoing coronary artery bypass surgery: impact of cardiopulmonary
bypass pump, hematocrit, gender, age, and body weight.
Anesth Analg.
2003;
97
958-963
- 14
Ferraris V A, Ferraris S P, Saha S P Society of Thoracic Surgeons Blood Conservation
Guideline Task Force; Society of Cardiovascular Anesthesiologists Special Task Force
on Blood Transfusion et al..
Perioperative blood transfusion and blood conservation in cardiac surgery: the Society
of Thoracic Surgeons and The Society of Cardiovascular Anesthesiologists clinical
practice guideline.
Ann Thorac Surg.
2007;
83
(5, Suppl)
S27-S86
- 15
Shevde K, Pagala M, Tyagaraj C et al..
Preoperative blood volume deficit influences blood transfusion requirements in females
and males undergoing coronary bypass graft surgery.
J Clin Anesth.
2002;
14
512-517
- 16 American Heart Association. Body Mass Index (BMI Calculator). January 20, 2011. Available
at: http://www.heart.org/HEARTORG/GettingHealthy/WeightManagement/BodyMassIndex/Body-Mass-Index-BMI-Calculator_UCM_307849_Article.jsp Accessed May 14, 2011
- 17 World Health Organization. Obesity. Available at: http://www.who.int/topics/obesity/en/ Accessed March 31, 2011
- 18
Ballotta A, Saleh H Z, El Baghdady H W et al..
Comparison of early platelet activation in patients undergoing on-pump versus off-pump
coronary artery bypass surgery.
J Thorac Cardiovasc Surg.
2007;
134
132-138
- 19
Paulitsch F S, Schneider D, Sobel B E et al..
Hemostatic changes and clinical sequelae after on-pump compared with off-pump coronary
artery bypass surgery: a prospective randomized study.
Coron Artery Dis.
2009;
20
100-105
- 20
Cavender M A, Rao S V.
Bleeding associated with current therapies for acute coronary syndrome: what are the
mechanisms?.
J Thromb Thrombolysis.
2010;
30
332-339
- 21
Ghosh S, Hu Y, Li R.
Cell density is a critical determinant of aromatase expression in adipose stromal
cells.
J Steroid Biochem Mol Biol.
2010;
118
231-236
- 22
Rosendaal F R, Helmerhorst F M, Vandenbroucke J P.
Female hormones and thrombosis.
Arterioscler Thromb Vasc Biol.
2002;
22
201-210
Chandrashekhar RamaiahM.D.
Division of Cardiothoracic Surgery, Department of Surgery, University of Kentucky
740 South Limestone, Room A301, Lexington, KY 40536-0284
eMail: crama01@uky.edu
